tACS Stimulation at Alpha Frequency Selectively Induces Inattentional Blindness

Abstract

Contemporary neurocognitive models implicate alpha oscillations as a top-down mechanism of cortical inhibition, instru- mental in the suppression of information that fails to reach conscious visual awareness. This suggests that alpha-band activity may play a key role in the phenomenon of inattentional blindness, however this has not yet been empirically examined. The current study employed transcranial alternating current stimulation (tACS) over occipital cortex at alpha, theta, and sham frequencies within an inattentional blindness task to delineate whether an exogenous manipulation of alpha oscillations has a modulatory effect on visual awareness of the unexpected stimulus. Results revealed that compared to theta and sham, those exposed to alpha tACS were more likely to be inattentionally blind to the unexpected stimulus. Findings extend current theoretical views of alpha by suggesting inattentional blindness may be explained as a suppression of irrelevant information via alpha-band.